TWI455230B - Liquid treatment device, liquid treatment method and memory medium - Google Patents

Description

Liquid processing device, liquid processing method and memory medium

The present invention relates to a technique for adjusting the ambient atmosphere of a liquid treatment of a substrate to be processed.

In a semiconductor manufacturing process, there is a process of performing liquid processing on a substrate to be processed such as a semiconductor wafer (hereinafter referred to as a wafer). The liquid treatment may be, for example, washing of a wafer by a cleaning liquid. The liquid processing unit used in the treatment includes a cup that receives, for example, a processing liquid, a rotation holding portion such as a rotary chuck provided in the cup, and a processing liquid supply nozzle that supplies the processing liquid to the substrate. Then, when the wafer is cleaned, a plurality of types of processing liquids are prepared, and various processing liquids are supplied to the surface of the rotating wafer in a predetermined order, and liquid processing is performed.

The rotary suction cup or the cup which is subjected to such liquid treatment is housed in a common casing and is isolated from the outside atmosphere. Then, by the clean air supplied from the FFU (Fan Filter Unit) located at the upper portion of the casing, a downward flow (downflow) of the clean air is formed in the casing, thereby suppressing the loading and unloading of the wafer or the liquid. The treatment causes particles or mist to keep the wafer and the frame clean.

In addition, in the cleaning process, an alkaline or acidic treatment liquid is supplied to the wafer, rinsed with a rinse liquid such as DIW (Delonized Water), and then IPA (IsoPropyl Alcohol) is supplied to perform simultaneous removal with IPA. The IPA of the liquid remaining on the surface of the wafer is dried. At this time, it must The humidity of the atmosphere around the wafer is suppressed to be low.

Further, in the liquid treatment on the surface of the wafer on which the metal wiring such as copper is formed, in order to prevent oxidation of the metal wiring, it is required to reduce the oxygen concentration on the surface of the wafer.

In this regard, for example, in Patent Document 1, it is described that a general flow of an inert gas is formed in the apparatus so as to cover the entire surface of the substrate to be treated, and the particles are prevented from being taken into the rinse liquid or the natural oxide film. The technique of generating a watermark. However, the supply of an inert gas to the entire liquid processing apparatus is a cause of an increase in liquid processing cost.

In addition, in the liquid processing apparatus which supplies the processing liquid to the lower surface and the side surface of the to-be-processed object and the etching process of this part, the top plate is provided so that it may cover the upper surface side of the to-be-processed object, An inert gas is supplied from the central portion of the top plate toward the upper surface of the object to be treated, and the technique of preventing the treatment liquid from being coated on the upper surface side of the object to be processed is prevented. However, the liquid processing apparatus is a device that performs liquid treatment on the lower surface or the side surface of the object to be processed. When performing liquid processing on the entire surface of the object to be processed, in order to avoid interference between the supply nozzle and the top plate of the treatment liquid, it is necessary to have A special supply mechanism for the treatment liquid. In addition, when moving in and out, it is necessary to have a moving mechanism that allows the top plate and the substrate holding the object to be processed to be in contact with each other without interfering with the object to be processed.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2003-174006: Request No. 1, FIG. [Patent Document 2] Japanese Laid-Open Patent Publication No. 2010-28059: claim 4, paragraph 0021, and 1

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid processing apparatus capable of forming a processing atmosphere suitable for liquid treatment such as a low-humidity atmosphere or a low-oxygen atmosphere on the surface of a substrate to be processed by a simple method. The processing method and the memory medium having the method are memorized.

The liquid processing apparatus according to the present invention is configured to supply a processing liquid to a surface of a substrate to be processed, and to perform liquid processing, the liquid processing apparatus comprising: a housing for performing liquid processing; and a rotation holding unit for rotating the holding portion The substrate to be processed is held in the frame and rotated about a vertical axis; and the processing liquid supply nozzle is configured to supply a processing liquid to a surface of the substrate to be processed held by the rotation holding portion; the cup, The cup is disposed around the rotation holding portion, and the first gas supply unit is disposed to be held by the rotation holding portion in order to form a processing atmosphere on the surface of the substrate to be processed. a position at which the substrate faces the flow of the entire surface of the substrate to be processed, and a downward flow of the first gas flowing into the cup; and a second gas supply unit for the first gas a region other than the descending flow, forming a second gas downflow different from the first gas, and the first gas supply The second portion and the second gas supply unit are provided in a ceiling portion of the casing.

The liquid processing apparatus described above may have the following features.

(a) a flared flow of the first gas downward flowing from the first gas supply unit toward the cup.

(b) The flow rate of the first gas supplied from the first gas supply unit is larger than the flow rate of the air current flowing toward the peripheral portion of the substrate to be processed by rotating the substrate to be processed.

(c) The flow rate of the first gas supplied from the first gas supply unit coincides with the flow rate of the second gas supplied from the second gas supply unit.

(d) The liquid processing apparatus further includes an exhaust portion that is provided inside the cup, mainly exhausts the first gas, and a second exhaust that is disposed outside the cup and mainly exhausts the second gas. unit.

(e) The first gas supply unit is configured to switch between the first gas and the second gas.

(f) the first gas supply unit is configured to be movable between a position at which the downflow of the first gas is formed and a retracted position inside the second gas supply unit, and the second gas supply unit is configured as described above When the first gas supply unit is located at the retracted position, a downward flow of the second gas toward the entire surface of the substrate to be processed is formed instead of the downward flow of the first gas.

(g) The substrate to be processed is a circular substrate, and the first gas supply unit has a circular discharge port having a diameter of 100 mm or more and a diameter equal to or smaller than the diameter of the substrate to be processed. Furthermore, in the spout, in order to discharge from the spout The entire first gas is supplied at a uniform flow rate, and a rectifying plate in which a large number of holes are formed is provided.

(h) The first gas is a dry gas or an inert gas.

According to the present invention, a downflow of a first gas for forming a processing atmosphere suitable for liquid processing is formed toward the entire surface of the substrate to be processed for liquid treatment, and is formed in the region other than the descending flow of the first gas. The descending flow of the second gas different in gas. Therefore, it is possible to locally form a processing atmosphere suitable for the liquid treatment performed on the entire surface of the substrate to be processed.

Hereinafter, an embodiment of a liquid processing apparatus according to the present invention will be described with respect to a liquid processing unit that washes both the front and back sides of the wafer W of the substrate to be processed. The liquid processing system 1 in which the liquid processing unit 2 is mounted includes a mounting block 11 on which the FOUP 100 accommodating the plurality of wafers W is placed, as shown in the perspective view of the external view of FIG. 1 and the cross-sectional view of the second drawing. The loading/unloading block 12 in which the wafer W is carried in and out of the FOUP 100 placed on the mounting block 11 and the receiving and discharging of the wafer W in the loading/unloading block 12 and the liquid processing block 14 in the subsequent stage are received. Block 13; and a liquid processing block 14 for applying a liquid treatment to the wafer W. When the mounting block 11 is set to the front, it is disposed adjacent to the mounting block 11, the loading/unloading block 12, the receiving block 13, and the liquid processing block 14 in the order from the front side.

The mounting block 11 will receive a plurality of wafers W in a horizontal state. The FOUP 100 is placed on the mounting table 111. The loading/unloading block 12 carries the wafer W. The receiving block 13 is for receiving the wafer W. The loading/unloading block 12 and the receiving block 13 are housed in the casing.

The loading/unloading block 12 has a first wafer conveying mechanism 121. The first wafer transfer mechanism 121 has a transfer arm 122 that holds the wafer W and a mechanism that moves the transfer arm 122 back and forth. Further, the first wafer transfer mechanism 121 has a mechanism that moves along the horizontal guide 123 (see FIG. 2) extending in the direction in which the FOUP 100 is arranged, and a vertical guide (not shown) that is disposed in the vertical direction. The moving mechanism is a mechanism that rotates the transport arm 122 in a horizontal plane. The wafer W is transported between the FOUP 100 and the receiving block 13 by the first wafer transport mechanism 121.

The receiving block 13 has a receiving rack 131 on which the wafer W can be placed. In the receiving block 13, between the loading and unloading block 12 and the transport mechanism of the liquid processing block 14 via the receiving scaffolding 131 (the first wafer transporting mechanism 121 and the second crystal described later) The circular transport mechanism 143) performs the wafer W reception.

The liquid processing block 14 has a configuration in which the liquid processing unit 141 in which the plurality of liquid processing units 2 are disposed and the transport unit 142 that transports the wafer W are housed in the housing. The transport unit 142 has a connection portion with the receiving block 13 as a base end, and a second wafer transport mechanism 143 is disposed in a space extending in the front-rear direction. The second wafer transfer mechanism 143 has a transfer arm 144 that holds the wafer W and a mechanism that moves the transfer arm 144 back and forth.

Further, the second wafer transfer mechanism 143 has a mechanism that moves along the horizontal guide 145 (see FIG. 2) extending in the front-rear direction, along the A mechanism for moving the vertical guide 146 in the vertical direction to rotate the transport arm 144 in a horizontal plane. The second wafer transport mechanism 143 transports the wafer W between the conventional scaffolding 131 and each of the liquid processing units 2 described above. As shown in Fig. 1, an FFU 147 for supplying clean air to the space of the liquid processing block 14 is provided above the conveying portion 142. As shown in FIG. 2, in the liquid processing unit 141, a plurality of liquid processing units 2 of a total of ten units, for example, five in total, are arranged in a direction in which the space in which the conveying unit 142 is formed extends.

The configuration of the liquid processing unit 2 provided in each of the liquid processing units 141 will be described with reference to Fig. 3 . The liquid processing unit 2 is a plate-type unit that performs liquid processing of the wafer W one by one by a rotation process. The liquid processing unit 2 is constituted by a processing space 21 formed in the casing and a gas supply unit 20 provided in an upper portion of the processing space 21 (the ceiling portion of the casing). The processing space 21 includes a rotating plate 33 that holds the wafer W, and a rotating shaft 341 that rotates the rotating plate 33 supported from the back surface (lower side) side by being rotated by a rotating motor (not shown); a liquid supply pipe 342 for supplying a processing liquid to the back surface (lower surface) of the wafer W in the shaft 341, and a processing liquid supply nozzle 35 for supplying a processing liquid to the surface (upper surface) side of the wafer W; The outer inner cup 32 is discharged from the processing liquid drawn from the rotating wafer W, and the outer cup cup 31 that accommodates the rotating plate 33 or the inner cup 32 and exhausts the air flowing from the upper side of the wafer W toward the peripheral side.

The rotating plate 33 is a disk-shaped member having an opening in the center, and a holding member 331 for holding and holding a plurality of wafers W is provided on the surface thereof. crystal The circle W is held at a position above the rotating plate 33 with a gap interposed therebetween. The processing liquid supplied from the liquid supply tube 342 through the central opening portion is diffused into the entire back surface of the wafer W through the gap. The rotating shaft 341 is held in a state of being rotatable about a vertical axis by a bearing portion 343 provided at the bottom of the processing space 21. The rotating plate 33, the rotating shaft 341, and the rotating mechanism described above correspond to the rotation holding portion of the present embodiment.

A support pin (not shown) for supporting the wafer W from the back side is provided on the upper end surface of the liquid supply pipe 342, and a lifting mechanism (not shown) for moving the liquid supply pipe 342 up and down is provided on the lower end side thereof. Then, the entire liquid supply pipe 342 is raised and lowered, and the liquid supply pipe 342 can be expanded and contracted from the opening of the rotary plate 33. Accordingly, the wafer W can be supported on the support pin, and the wafer W can be moved up and down between the position where the wafer W is transferred between the transfer arm 144 and the processing position on the rotary plate 33.

The liquid supply pipe 342 can supply an alkaline treatment liquid such as SC1 liquid (a mixture of ammonia and hydrogen peroxide) or a dilute hydrofluoric acid aqueous solution (hereinafter, DHF (Diluted Hydro Fluoric Acid) or the like to the back surface of the wafer W. Washing liquid for rinsing and washing of treatment liquid, DIW, etc.

Further, the processing liquid supply nozzle 35 that supplies the processing liquid to the surface of the wafer W is supported by the nozzle arm 351, and can be retracted from the processing position above the wafer W held by the rotating plate 33 and from the processing position. Move between retracted positions. The treatment liquid supply nozzle 35 can supply the IPA for drying treatment of the organic solvent in addition to the alkaline or acidic treatment liquid and the rinse liquid.

The inner cup 32 shown in Fig. 3 is arranged to surround the rotated plate 33. The annular member holding the wafer W can be discharged through the liquid discharge pipe 321 connected to the bottom surface. Further, an exhaust pipe 311 for exhaust gas is provided on the bottom surface of the outer cup 31, and the air flow mainly flowing from the upper side of the wafer W toward the peripheral portion side is discharged. On the upper surface of the outer cup cover 31 and the inner cup cover 32, an opening having a larger diameter than the wafer W is formed, and the wafer W supported by the liquid supply tube 342 is moved in the vertical direction through the opening.

The processing space 21 has an opening on the side facing the conveying portion 142, and a switch door 211 for opening and closing the opening is provided. By opening the opening and closing door 211, the carrying arm 144 can enter the processing space 21 through the opening. As shown in FIG. 3, an exhaust pipe 212 in which a descending flow of clean air formed in the processing space 21 is formed at the bottom of the processing space 21 is provided.

In the liquid processing unit 2 having the above-described configuration, after various processing liquids are supplied to the surface of the wafer W to be rotated, IPA drying by IPA is performed in order to remove the liquid remaining on the surface of the wafer W. As in the prior art, when the IPA is dried, it is necessary to suppress the humidity of the atmosphere around the wafer W to be low, but the inert gas or dry gas such as nitrogen is more expensive than the general clean air. Then, the liquid processing unit 2 according to the present embodiment is provided with a gas having a small amount of water contained in the area where the IPA is dried, and the humidity of the processing atmosphere is kept low, and the supply of the area which does not affect the drying of the IPA is provided. The configuration of the operating cost of the apparatus can be suppressed without performing the normal clean air in which the moisture content is adjusted. Hereinafter, the details of this configuration will be described.

As shown in FIG. 3, a gas supply unit 20 is provided above the processing space 21. The gas supply unit 20 is used to be held toward the rotating plate The entire surface of the wafer W of 33 is formed with a first gas supply unit 23 for reducing the downward flow of clean air (corresponding to a first gas, hereinafter referred to as "dry gas") containing water, and for forming the same A second gas supply unit that forms a descending flow of general clean air (corresponding to a second gas, hereinafter referred to as "general gas"), which is not subjected to a treatment for reducing the water content, in a region other than the region in which the first gas is to be reduced. 22 constitutes.

First, when the second gas supply unit 22 is described, the second gas supply unit 22 is a frame-shaped chamber that covers the entire ceiling of the processing space 21 in which the liquid processing is performed, as shown in FIGS. 3 and 4 . In general, an opening portion 221 is provided on the side wall of the transport portion 142 on the surface. The opening 221 takes in the general gas supplied from the FFU 147 provided above the conveying unit 142 into the second gas supply unit 22. Further, for convenience of illustration, the description of the outer cup 31 or the inner cup 32 is omitted in the oblique view of Fig. 4 .

The bottom plate 222 of the second gas supply unit 22 constitutes a ceiling surface of the processing space 21, and a plurality of vent holes 223 are formed in the bottom plate by punching or the like. The general gas taken into the second gas supply unit 22 is introduced into the processing space 21 through the vent holes 223, and then exhausted by the exhaust pipe 212 mainly disposed at the bottom of the processing space 21. . As a result, in the processing space 21, a downward flow of a general gas flowing from the ceiling surface side toward the bottom side is formed.

The first gas supply unit 23 is disposed inside the chamber constituting the second gas supply unit 22. The first gas supply unit 23 is disposed above the wafer W so as to face the wafer W held by the rotary plate 33. The gas system supplied from the first gas supply unit 23 is above the wafer W A downward flow of dry gas is formed toward the entire surface. Further, the gas flowing from the upper side of the wafer W to the entire surface is mainly exhausted from the exhaust pipe 311 provided in the outer cup 31.

Here, as shown in FIG. 7, when the wafer W is rotated, the viscous force acting between the wafer W and the surrounding gas and the centrifugal force received by the gas from the wafer W are acted upon from the wafer. The gas taken in above W is swept toward the peripheral portion side of the wafer W. In other words, a flared airflow is formed from the first gas supply unit 23 toward the peripheral edge side of the wafer W. Here, when the dry gas having the same amount or more as the gas flow swept toward the peripheral portion side of the wafer W is supplied from the first gas supply unit 23 without turbulent gas flow, the presence of the dry gas can be suppressed. The general gas around the flared gas stream is mixed into the gas stream of the dry gas. As a result, the entire surface of the wafer W can be covered with a dry gas, and moisture can be introduced into the surface of the wafer W, so that the surface of the wafer W on which the liquid treatment is performed and the atmosphere (processing atmosphere) around it can be locally low. Further, since the general gas existing around the flared shape forms a downward flow, the inside of the processing space 21 can be kept clean.

In order to achieve the above-described effects, the first gas supply unit 23 according to the present embodiment is placed inside the flat tray-shaped lid member 233 which is open at the lower side, for example, as shown in FIG. For example, three rectifying plates (the first rectifying plate 234, the second rectifying plate 235, and the third rectifying plate 236) having a plurality of flow holes 237 formed by punching or the like are arranged in the vertical direction. As a result, as shown in FIG. 6, a ceiling in which the dry gas flows through the cover member 233 and the first rectifying plate are formed in the first gas supply unit 23 Between 234, the space between the first rectifying plate 234 and the second rectifying plate 235 and between the second rectifying plate 235 and the third rectifying plate 236. Then, the dry gas supplied from the air supply pipe 231 connected to the ceiling surface of the lid member 233 flows through the respective holes through the flow holes 237, and is finally introduced into the processing space 21 through the flow holes 237 of the third rectifying plate 236. Inside, it flows down toward the surface of the wafer W.

Further, the flow holes 237 are arranged such that the arrangement positions of the flow holes 237 are shifted in the horizontal direction so as not to be vertically arranged between the rectifying plates 234 to 236 disposed adjacent to each other. As a result, the dry gas system flows into the first gas supply unit 23 while being divided into a stepped shape as shown by the broken line in Fig. 6, and is supplied into the processing space 21 at a uniform flow rate. Further, as the rectifying plates 234 to 236 shown in Fig. 6 are on the downstream side, the number of the flow holes 237 is increased, the opening ratio is increased, and the outflow speed of the dry gas from the respective rectifying plates 234 to 236 is gradually reduced. . The method of changing the aperture ratio of the flow regulating plates 234 to 236 is not limited to this example. For example, even if the number of holes of the flow holes 237 of the respective rectifying plates 234 to 236 is almost the same, the flow path of the rectifying plate on the downstream side is increased. The aperture can also be.

In addition, the third rectifying plate 236 disposed at the lowermost portion of the first gas supply unit 23 corresponds to the discharge port of the dry gas when viewed from the processing space 21 side. When the area of the discharge port of the dry gas is too small, and the dry gas of the same amount or more as that of the gas stream swept from the first gas supply unit 23 toward the peripheral portion of the wafer W is supplied, the outflow speed of the dry gas is too fast. As a result, the flared airflow turbulently flows into the surrounding general gas, so that moisture is introduced into the surface of the wafer W. That is. In order to form a dry gas over the wafer W In the flared downflow, the dry gas having the same amount or more as the gas stream swept out toward the peripheral portion of the wafer W must be supplied from the discharge port having an area where the outflow rate of the dry gas is not too fast. Thus, the inventors have studied the appropriate size of the spout. As a result, it is understood that when the liquid processing is performed while rotating the wafer W of 300 mm, the diameter of the discharge port is preferably 100 mm or more.

Further, when the diameter of the discharge port of the dry gas is increased to be larger than the diameter of the wafer W or the diameter of the opening of the outer cup 31, it is not supplied to the surface of the wafer W and flows to the outside of the outer cup 31. Exhaust, the amount of loss of dry gas increases. Therefore, the diameter of the discharge port of the dry gas is preferably, for example, less than the diameter of the wafer W.

When a liquid crystal treatment is performed while rotating a 300 mm wafer while the liquid crystal treatment is being performed, the first gas supply unit having a discharge port having a diameter of 100 mm or more and a diameter of the wafer W or less is used. 23. It is preferable to supply the outflow speed to the extent that the dry gas does not get caught in the surrounding general gas, for example, the flare flow rate maintains the laminar flow rate. Accordingly, it is possible to effectively reduce the introduction of moisture onto the surface of the wafer W, and locally maintain the atmosphere (processing atmosphere) of the wafer W and its surroundings at a low humidity.

In this case, it is preferable that the average outflow rate of the general gas supplied from the second gas supply unit 22 coincides with the average outflow rate of the dry gas supplied from the first gas supply unit 23. The "synchronization" of the flow rates of the general gas and the dry gas is not limited to the case where the two outflow speeds are strictly coincident. The difference between the outflow speed of the general gas and the dry gas, if it does not cause When the horn-like airflow formed by the rotation of the wafer W is turbulent, and the airflow on one side is not involved in the turbulent flow of the other side, the airflow can be regarded as flowing out. The speed is the same.

As shown in FIG. 4 and FIG. 5, the first gas supply unit 23 is provided with a branch pipe 232 that is branched from the air supply pipe 231, and uniformly supplies the dry gas to the ceiling surface of the cover member 233 and the first rectifying plate 234. The space between. It is preferable that the discharge port of the branch pipe 232 and the flow hole 237 of the first flow regulating plate 234 are disposed at positions shifted in the horizontal direction.

As shown in Fig. 3, the piping connected to the base end side of the air supply pipe 231 is branched into the dry gas pipe 401 and the bypass pipe 402 via the switching valve V1. The general gas supplied by the upstream side fan 41 and the particulate filter 42 is reduced in moisture content by the moisture removing unit 44 provided between the dry gas tubes 401. The moisture removal unit 44 is configured to be formed by filling a filling layer such as silicone, or a cooling tube through which a refrigerant flows around a space in which a general gas flows, and condensing the contained water. It is not limited to a specific method. When the IPA is dried, the relative humidity of the dry gas supplied from the moisture removing unit 44 is preferably 10% or less from the viewpoint of making the processing atmosphere of the wafer W low. Here, the dry gas supplied to the first gas supply unit 23 may be received from the outside to the factory even by a common power pipe or the like.

Further, in the first gas supply unit 23 in this example, the general gas passing through the bypass pipe 402 of the bypass moisture removal unit 44 may be supplied, and the flow paths 401 and 402 are switched by the flow path switching valve 43. .

The liquid processing system 1 having the above-described configuration is as shown in Figs. 2 and 3 It is connected to the control unit 5 as shown. The control unit 5 is composed of a computer including a CPU and a memory unit (not shown), and a program is recorded in the memory unit, and the program is edited for the liquid processing system 1 or each liquid processing unit 2, that is, it is loaded from the load. The FOUP 100 of the block 11 takes out the wafer W, carries it into each of the liquid processing units 2, and performs liquid processing, and then returns to the FOUP 100 to control the step (command) group. The program is stored in a memory medium such as a hard disk, a CD, a magneto-optical disk, a memory card, etc., from which the computer is installed.

In particular, the control unit 5 outputs a control signal to the various switching valves V1, 43 and the like as shown in FIG. 3, and can switch the supply timing or supply amount of the processing liquid, the discharge target of the processing liquid, or the like, or the first gas supply unit. 23 The type of clean air that is supplied.

In the case of the liquid processing system 1 having the above-described configuration, when the liquid processing system 1 is configured as described above, first, a wafer W is taken out from the FOUP 100 placed on the mounting block 11 by the first wafer transfer mechanism 121. This operation is performed continuously in the scaffolding 131. The wafer W placed on the receiving scaffold 131 is sequentially transported by the second wafer transporting mechanism 143 in the transport unit 142, and is carried into any of the liquid processing units 2 and held in the rotating plate. 33.

When the loading of the wafer W is completed, the processing liquid supply nozzle 35 is moved to a position above the center side of the wafer W, and the wafer W is rotated at, for example, 10 to 1000 rpm, facing the surface side of the wafer W and An alkaline treatment liquid such as SC1 liquid is supplied to the back side. Accordingly, a liquid film of the chemical liquid is formed on the upper and lower sides of the wafer W, and the particulate or organic contaminant is removed by the alkaline treatment liquid. Next, it will be supplied to both sides of the wafer W. After the chemical solution is switched to the rinse liquid and rinsed, the supply of the rinse liquid is stopped.

In the case of the alkali washing and the rinsing and washing, the moisture in the clean air supplied to the surface of the wafer W is difficult to directly form a watermark. In addition, when a highly potent chemical liquid is used for washing, it is preferable to contain moisture in clean air. Here, in this period, the flow path switching valve 43 shown in FIG. 3 is switched to the side of the bypass pipe 402, and the general gas is supplied from the first gas supply unit 23 (Fig. 9). Further, the general gas is continuously supplied from the second gas supply unit 22. In the process of the liquid treatment in which the water influence is less, the general gas is supplied by the bypass moisture removal unit 44, and the operation efficiency of the moisture removal unit 44 is lowered to reduce the running cost. In the period of the liquid treatment in which the influence of the water is small, the gas supplied from the first gas supply unit 23 may be, for example, a mixed gas of a dry gas and a general gas.

When the rinsing and washing is completed, the DHF liquid of the acidic treatment liquid is supplied to the front and back sides of the wafer W while rotating at, for example, 10 rpm to 1000 rpm. Accordingly, a liquid film of the DHF liquid is formed on the surfaces, and a liquid treatment for removing the natural oxide film formed on the surface of the wafer W is performed. Then, after a predetermined period of time has elapsed, the treatment liquid is switched to the rinse liquid to perform rinse washing.

In the above-described operation, during the period of the liquid treatment by the acidic treatment liquid, for example, the first gas supply unit 23 is connected to the side of the bypass pipe 402 to supply the general gas. Then, when it is time to perform, for example, rinsing and washing, the first gas is prepared in preparation for IPA drying subsequent to rinsing washing. The connection destination of the body supply unit 23 is switched to the side of the dry gas pipe 401, and dry gas is supplied into the processing space 21 to form a tumble-like downward flow of the dry gas (Fig. 9).

In this way, the rinse is finished, and when the downflow formed toward the surface of the wafer W is switched to dry gas, the number of rotations of the wafer W is adjusted to, for example, 1000 rpm, and the treatment liquid supplied to the surface is switched to IPA. . As a result, IPA drying by IPA is carried out to completely remove the liquid such as the rinse liquid remaining on the surface of the wafer W. Further, the rinse liquid or the like remaining on the back surface of the wafer W is dried by the rotation of the wafer W.

At this time, FIG. 8 schematically shows the flow state of the descending flow of the clean air formed in the processing space 21. In the figure, the gas flow of the dry gas is indicated by a broken line at a short interval, and the gas flow of the general gas is indicated by a long interval of a broken line. The dry gas that has flowed out of the first gas supply unit 23 is a downward flow from the upper side of the wafer W toward the entire surface of the airflow formed by the rotation of the wafer W (see FIG. 7). In addition, the general gas supplied from the second gas supply unit 22 forms a downward flow that flows so as to surround the downward flow of the dry gas supplied from the first gas supply unit 23. Then, since the descending flow of the dry gas is formed in the region above the surface of the wafer W, the surrounding atmosphere is prevented from entering the processing atmosphere on the surface of the wafer W. Further, since the downward flow of the general gas is formed around the descending flow of the dry gas, the atmosphere in the processing space 21 is prevented from rising.

As a result, moisture is suppressed from being introduced into the processing atmosphere on the surface of the wafer W subjected to IPA drying. Accordingly, it is possible to suppress the intake of moisture into the IPA and to reduce the generation of the watermark. Furthermore, it is possible to prevent the processing space 21 from being The atmosphere rises and the treatment space 21 remains clean.

In this manner, when the predetermined time IPA is supplied, the state in which the rotation of the wafer W is continued is maintained, the supply of the IPA is stopped, and the IPA of the surface of the wafer W is removed. When the drying of the wafer W is completed, the liquid processing of the wafer W is completed.

Here, the ninth diagram shows an example of a procedure for supplying dry gas and general gas from the first gas supply unit 23, and the gas supply method of the dry gas and the general gas is not limited to this example. For example, when the dry gas is supplied, the supply amount of the dry gas from the first gas supply unit 23 is set to 200 L/min, and the supply amount of the general gas from the second gas supply unit 22 is set to 800 L/min. At the time of supply of the general gas, the supply of the dry gas from the first gas supply unit 23 is stopped, and the supply amount of the general gas from the second gas supply unit 22 may be increased to 1000 L/min. Even if the supply of the dry gas is stopped, the general gas supplied from the second gas supply unit 22 flows into the upper portion of the wafer W. Therefore, the general gas forms a flared gas flow as shown in Fig. 7 and flows on the entire surface of the wafer W. It is exhausted from the exhaust pipe 311. At this time, by supplying the supply amount of all the gas supplied to the processing space 21 by the supply and stop periods of the dry gas, the pressure fluctuation in the processing space 21 can be suppressed.

In addition, the switching timing of the general gas and the dry gas is not limited to the example shown in FIG. 9, and the dry gas is supplied from the first gas supply unit 23 at a timing at which the processing atmosphere on the surface of the wafer W is low in humidity. Just fine.

The wafer W that has been subjected to the liquid processing is carried out from the liquid processing unit 2 by the transport arm 144, placed on the receiving scaffold 131, and the wafer W is taken from the scaffold 131 by the first wafer transport mechanism 121. Return to FOUP100. Such as As a result, the plurality of wafers W are sequentially subjected to liquid processing by the liquid processing unit 2 provided in the plurality of liquid processing systems 1.

When the liquid processing unit 2 according to the present embodiment is used, the following effects are obtained. A downward flow of the dry gas is formed toward the entire surface of the wafer W subjected to the liquid treatment, and a downward flow of the general gas is formed in a region surrounding the downward flow of the dry gas, so that the dry gas is locally supplied to the wafer W. During the IPA drying process, the processing atmosphere on the surface of the wafer W is maintained at a low humidity to suppress the formation of a watermark. Further, by reducing the flow of the general gas which does not reduce the moisture contained in the region which does not affect the result of the drying of the IPA, the consumption of the dry gas is higher than when the dry gas is supplied to the entire processing space 21 Only a small amount can be used to reduce the supply cost of dry gas.

In addition, since any of the general gases supplied from the first gas supply unit 23 and the general gas supplied from the second gas supply unit 22 form a downward flow in the processing space 21, the processing space 21 can be prevented. The atmosphere inside is raised and kept clean.

In addition, by providing the first gas supply unit 23 for supplying dry gas to the upper portion of the processing space 21, it is not necessary to provide a treatment for the surface of the wafer W in the processing space 21 as in the case of the top plate described in the prior art. The atmosphere is a mechanism for low humidity or a supply mechanism for a special treatment liquid to avoid interference with the top plate, and the device configuration can be simplified. Further, since the lifting operation of the top plate is not performed, the downward flow formed in the processing space 21 is not disturbed, and the supply of dry gas can be performed.

Above, in the implementation mode described using FIG. 3, although dry The gas is a first gas that descends toward the entire surface of the wafer W, and a general gas is used as the second gas that forms a downward flow in a region surrounding the downward flow of the first gas. However, the types of the first gas and the second gas are not Limited to this. For example, an inert gas such as nitrogen gas containing no water may be used as the first gas.

In addition, when performing a liquid treatment in which a wafer W having a metal wiring such as copper is formed in a process which is required to be treated under an atmosphere containing a large amount of oxygen, when oxygen is introduced into the surface of the wafer W, There is a case where the oxidation of the copper wiring is adversely affected. At this time, even if an inert gas containing no oxygen such as nitrogen or argon is used as the first gas, and a general gas is used as the second gas, a downward flow of each gas may be formed in the processing space 21. Accordingly, the processing atmosphere of the wafer W can be made low-oxygen.

When it is desired to reduce the amount of introduction of oxygen into the surface of the wafer W in accordance with the type of the treatment liquid, all of the chemical liquid treatment, the rinsing treatment, and the drying treatment are covered, and the first gas is supplied from the first gas supply unit 23 at all times. It is better.

Then, the first gas supply unit 23a shown in FIG. 10 is an example in which a porous body 238 made of a sintered body of ceramic or ceramic particles or the like is provided on the lower surface of the lid member 233 to uniformly supply the first gas. Others, even if it is changed to the rectifying plate 236 or the porous body 238, the mesh may be arranged. In addition, the second gas supply unit 22 is not limited to the bottom plate 222 in which the vent hole 223 is formed by punching, and the second gas is supplied to the processing space even by the bottom plate 222 formed of a porous body or a mesh. Of course, within 21.

In addition, FIG. 11 and FIG. 12 show a liquid which can be formed by switching the descending flow of the first gas and the descending flow of the second gas toward the entire surface of the wafer W by moving the first gas supply unit 23b. An example of the processing unit 2a. In this example, the first gas supply unit 23b can be moved up and down inside the second gas supply unit 22 by the elevating mechanism 239. In the period in which the downflow of the first gas is not formed, as shown in FIG. 11, the first gas supply unit 23b is evacuated to the retracted position on the upper side, and is disposed in the first gas supply unit. The vent hole 223 of the bottom plate 222 on the lower side of the 23b supplies the second gas to the surface of the wafer W. Then, when liquid processing in which the processing atmosphere of the wafer W is to be formed by the first gas is performed, the first gas supply unit 23b is lowered as shown in Fig. 12, and the bottom plate 222 is covered by the first gas supply unit 23b. A part of the first gas is supplied through the vent hole 223 of the bottom plate 222.

In addition, the height position of the first gas supplied from the first gas supply unit 23 may be a flat top without being at a height position from the second gas supply unit 22 to supply the second gas. For example, as shown in the liquid processing unit 2b of Fig. 13, the flow hole 237 of the first gas supply unit 23 is protruded to the vent hole 223 of the second gas supply unit 22 (in this example, the processing space 21) The ceiling surface is at a low position, and the first gas is supplied from a position lower than the second gas to suppress the entrapment of the second gas.

Further, the configuration of the other second gas supply unit 22 is not limited to the configuration examples shown in FIGS. 3 and 4 . For example, even if the flow rate adjusting valve 224 is provided in the opening portion 221 as in the second gas supply portion 22 shown in the liquid processing unit 2c of Fig. 14, the general gas from the vent hole 223 is increased or decreased. The outflow speed of the body may be equal to the flow rate of the dry gas supplied from the first gas supply unit 23. In addition, as shown in Fig. 15, the FFU 225 may be provided on the upper surface of the second gas supply unit 22, and the general gas may be supplied to each of the liquid processing units 2d from the air supply duct 226.

In the above, the case where the liquid processing is performed while rotating the semiconductor wafer will be described. However, the processing target is not limited to the semiconductor wafer, and the processing target is rotated while being processed. For example, a glass substrate for a photomask, a glass substrate for liquid crystal, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for a disk, a substrate for a disk, and a substrate for a magneto-optical disk are also included.

In the liquid processing unit 2 that supplies the processing liquid for supplying the alkaline, acidic, and organic solvent to the wafer W, the liquid processing unit 2 of the present invention is applied. However, the liquid processing apparatus can be implemented. The type of liquid treatment is not limited to this. For example, the present invention can be applied to a liquid processing apparatus which is required to rotate a substrate to be processed on a wafer or an angular substrate while forming a processing atmosphere suitable for liquid processing such as low humidity or low oxygen.

In addition, although the gas supplied from the first gas supply unit 23 and the second gas supply unit 22 is a dry gas or a general gas, the gas to be supplied is not limited thereto. For example, a gas adjusted to a temperature higher than a normal temperature is supplied from the first gas supply unit 23, and a normal gas at a normal temperature may be supplied from the second gas supply unit 22. In this way, in the process of supplying the high-temperature processing liquid to the wafer W, In order to suppress the temperature drop of the treatment liquid, the treatment is promoted. In addition, even if the gas passing through the chemical filter is supplied from the first gas supply unit 23, the general gas may be supplied from the second gas supply unit 22. As a result, the processing atmosphere in which the chemical substance is introduced onto the surface of the wafer W can be suppressed, and an unnecessary chemical reaction on the surface of the wafer W can be prevented. Further, even if the gas is not supplied from the first gas supply unit 23, an acid or an alkali or an organic gas may be supplied. In this way, even when different kinds of chemical liquids are used for the processing of the wafer W, the processing atmosphere on the surface of the wafer W can be quickly replaced, and the generation of particles can be suppressed. Further, even if a chemical liquid used for the treatment of the wafer W is blended, a gas containing an acid or an alkali or an organic gas may be supplied from the first gas supply unit 23. As a result, even when the treatment of the wafer W is performed using a highly deteriorated chemical liquid, the deterioration of the chemical liquid can be suppressed by making the processing atmosphere on the surface of the wafer W the same as that of the chemical liquid. When a highly volatile chemical solution such as a diluent is used, it is possible to easily diffuse the chemical solution onto the surface of the wafer W while suppressing the volatility.

In addition, the flow rate of the supplied gas may be changed while being supplied from the first gas supply unit 23. In other words, since the amount of the airflow swept toward the peripheral portion of the wafer W is changed by the rotational speed of the wafer W, the supply amount from the first gas supply unit 23 is changed in accordance with the rotational speed of the wafer W. . Specifically, the supply amount is increased when the number of rotations is increased, and the supply amount is decreased when the number of rotations is decreased. Accordingly, a trumpet-shaped downflow can be formed with a minimum supply amount required.

W‧‧‧ wafer

1‧‧‧Liquid treatment system

2, 2a ~ 2d ‧ ‧ liquid handling unit

21‧‧‧Handling space

22‧‧‧2nd gas supply department

23, 23a, 23b‧‧‧1st gas supply department

234‧‧‧1st rectification board

235‧‧‧2nd rectification board

236‧‧‧3rd rectification board

33‧‧‧Rotating plate

35‧‧‧Processing liquid supply nozzle

44‧‧‧Water Removal Department

5‧‧‧Control Department

Fig. 1 is a perspective view showing the appearance of a liquid processing system according to an embodiment of the present invention.

Fig. 2 is a transverse plan view of the above liquid processing system.

Fig. 3 is a longitudinal side view of the liquid processing unit provided in the liquid processing system.

Fig. 4 is a partially cutaway perspective view showing the internal structure of the liquid processing unit.

Fig. 5 is an exploded perspective view of the first gas supply unit provided in the liquid processing unit.

Fig. 6 is a longitudinal side view of the first gas supply unit.

Fig. 7 is an explanatory view showing the flow of the airflow formed above the wafer rotated about the vertical axis.

Fig. 8 is an explanatory view showing the flow of gas in the above-described processing unit in the liquid processing period.

Fig. 9 is a timing chart showing the correspondence relationship between the type of the processing liquid supplied to the wafer and the type of the gas supplied from the first gas supply unit.

Fig. 10 is a longitudinal sectional side view showing another example of the first gas supply unit.

Fig. 11 is a first explanatory diagram of a liquid processing unit including a first gas supply unit having a lift type.

Fig. 12 is a second explanatory diagram of a liquid processing unit including a first gas supply unit having a lift type.

Fig. 13 is a liquid processing unit for changing the arrangement height of the first gas supply unit.

Fig. 14 is an explanatory view showing a configuration example of a first gas supply unit including a flow rate adjusting valve.

Fig. 15 is an explanatory view showing a configuration example of a first gas supply unit including an FFU.

W‧‧‧ wafer

2‧‧‧Liquid Handling Unit

5‧‧‧Control Department

20‧‧‧Gas Supply Department

21‧‧‧Handling space

22‧‧‧2nd gas supply department

23‧‧‧1st gas supply department

31‧‧‧ outer cup

32‧‧‧ inner cup

33‧‧‧Rotating plate

35‧‧‧Processing liquid supply nozzle

41‧‧‧Send fan

42‧‧‧Particle filter

43‧‧‧Flow path switching valve

44‧‧‧Water Removal Department

212‧‧‧Exhaust pipe

221‧‧‧ openings

222‧‧‧floor

223‧‧‧vents

231‧‧‧ gas supply pipe

311‧‧‧Exhaust pipe

321‧‧‧Draining tube

331‧‧‧ Keeping components

341‧‧‧Rotary axis

342‧‧‧Liquid supply tube

343‧‧‧ Bearing Department

351‧‧‧Nozzle arm

401‧‧‧dry gas pipe

402‧‧‧bypass

V1‧‧‧ switching valve

Claims (16)

A liquid processing apparatus that supplies a processing liquid to a surface of a substrate to be processed and performs liquid processing, the liquid processing apparatus comprising: a housing for performing liquid processing; and a rotation holding unit for holding the inside of the housing The substrate is processed to rotate about a vertical axis; and the processing liquid supply nozzle is configured to supply a processing liquid to a surface of the substrate to be processed that is held by the rotation holding portion; the cup is disposed around the rotation holding portion The first gas supply unit is disposed at a position opposed to the substrate to be processed held by the rotation holding unit in order to form a processing atmosphere suitable for the liquid processing, and is formed to flow on the substrate to be processed. a downward flow of the first gas flowing into the cup; and a second gas supply unit for forming a second gas downflow different from the first gas in a region other than the downward flow of the first gas That is, a downward flow that flows on the outer side of the surface of the substrate to be processed, and the first gas supply unit and the second gas supply unit are provided in a ceiling portion of the casing. The first gas supply unit is supplied by the so treated substrate is rotated toward the flow stream above the peripheral edge portion of the first flow of gas from the rotation center to be processed of the substrate. The liquid processing apparatus according to the first aspect of the invention, wherein the first gas is supplied from the first gas supply unit, and the second gas is supplied from the second gas supply unit. The outflow speed is the same. The liquid processing apparatus according to the first or second aspect of the invention, wherein the first gas supply unit is configured to switch between a downward flow of the first gas and a downward flow of the second gas. The liquid processing apparatus according to the first or second aspect of the invention, wherein the first gas supply unit is configured to switch between the formation of the downward flow of the first gas and the stop of the supply of the first gas, and the second gas supply. When the first gas supply unit stops the supply of the first gas, the second gas is increased only at a flow rate corresponding to the amount of decrease of the first gas, thereby forming a downward flow that flows into the surface of the substrate to be processed. The liquid processing apparatus according to the first or second aspect of the invention, wherein the first gas supply unit is configured to be movable between a position where the downward flow of the first gas is formed and a retracted position, and the second gas supply The part is configured to form a downward flow of the second gas toward the entire surface of the substrate to be processed, in place of the downward flow of the first gas, when the first gas supply unit is located at the retracted position. The liquid processing apparatus according to claim 1 or 2, wherein the substrate to be processed is a circular substrate, and the first gas supply unit has a circular discharge port, and the circular discharge port has a diameter of 100 mm. The diameter below the diameter of the substrate to be processed. The liquid processing apparatus according to the sixth aspect of the invention, wherein the discharge port is provided with a flow regulating plate in which a plurality of holes are formed at a uniform flow rate from the entire discharge port. The liquid processing apparatus according to claim 1 or 2, wherein the first gas is a dry gas or an inert gas. A liquid processing method for supplying a treatment liquid to a surface of a substrate to be processed for liquid treatment, the liquid processing method comprising: a process of holding a substrate to be processed and rotating about a vertical axis; and a surface of the substrate to be processed for the rotation In order to form a processing atmosphere suitable for the liquid processing, the first gas is supplied from above the substrate to be processed, and the first gas flowing from the rotation center toward the peripheral portion on the surface of the substrate to be processed is formed. a process of descending flow; and a second gas downflow different from the first gas in a region other than the descending flow of the first gas, that is, a lower flow on the outer side than the surface of the substrate to be processed In the flow project, the descending flow of the first gas includes a first gas having a flow rate of a gas flowing from a rotation center of the substrate to be processed toward a peripheral portion by rotating the substrate to be processed. The liquid processing method as recited in claim 9, wherein The first gas system is supplied so that the gas flow flowing toward the peripheral edge portion of the substrate does not flow in accordance with the rotation of the substrate to be processed. The liquid processing method according to claim 9 or 10, wherein the first gas and the second gas system are supplied so that the second gas does not mix into the downward flow of the first gas. The liquid processing method according to claim 9 or 10, wherein the flow rate of the descending flow of the first gas coincides with the flow velocity of the descending flow of the second gas. The liquid processing method according to claim 9 or 10, wherein the lowering flow of the first gas is switched to form a lowering of the second gas flowing from the center of rotation toward the peripheral portion on the surface of the substrate to be processed which is rotated. Flow of engineering. The liquid processing method according to claim 9 or 10, further comprising the step of switching the formation of the downflow of the first gas, stopping the supply of the first gas, and stopping the supply of the first gas, The second gas is increased in a flow rate corresponding to the amount of decrease in the first gas to form a downflow flowing into the surface of the substrate to be processed. The liquid processing method according to claim 9 or 10, wherein the first gas is a dry gas or an inert gas. A memory medium storing a computer program used in a liquid processing apparatus that supplies a processing liquid to a surface of a substrate to be processed and liquid-treated, wherein the memory medium is characterized by the program grouping step group to implement the patent application scope ninth The liquid treatment method as described in any one of the fifteenth.